Sapphire crystals are used in a variety of applications. For example, sapphire sheets can be used for various demanding, high performance military and commercial applications, such as ballistic and targeting windows. Further improvement of sapphire sheets, in particular in the dimensional stability during production of large and thick sapphire sheets is desired.
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the invention.